Solvatochromism effects on the dipole moments and photo-physical behavior of some azo sulfonamide dyes.

Absorption and emission spectra of three azo sulfonamide dyes with various molecular structures have been studied in different solvents. The solute photo-physical behavior depends strongly on the solvent-solute interactions and solvent microenvironment. In order to understand the effect of intermolecular interactions on spectral behaviors of these dyes in different solvents and to conceive nature and extent of solvent-solute interactions the spectral variations were analyzed by the linear solvation energy relationships concept. In addition, by means of solvatochromic method the dipole moments of these dyes, in ground and excited states, were investigated.

Photo-responsive polymer with erasable and reconfigurable micro- and nano-patterns: an in vitro study for neuron guidance.

The interaction of cells with nanoscale topography has proven to be an important modality in controlling cell responses. Topographic parameters on material surfaces play a role in cell growth. We have synthesized a new bio compatible polymer containing photoswitching molecules. Stripepatterned (groove/ridge pattern) were patterned and erased with ease on this bio azopolymer with two different set-ups: one with the projection of an optical interference pattern and the other one by molecular self-organization with one single laser beam. These two set-ups allow the re-writing of pattern after erasing and its inscription in vitro. PC12 cells were cultured on the bio-photoswitching patterned polymer and compared with PC12 cells growing on a well know substrate: poly-L-lysine. This result is of interest for facilitating contact guidance and designing reconfigurable scaffold for neural network formation in vitro.

Experimental and theoretical UV characterizations of acetylacetone and its isomers.

Cryogenic matrix isolation experiments have allowed the measurement of the UV absorption spectra of the high-energy non-chelated isomers of acetylacetone, these isomers being produced by UV irradiation of the stable chelated form. Their identification has been done by coupling selective UV-induced isomerization, infrared spectroscopy, and harmonic vibrational frequency calculations using density functional theory. The relative energies of the chelated and non-chelated forms of acetylacetone in the S0 state have been obtained using density functional theory and coupled-cluster methods. For each isomer of acetylacetone, we have calculated the UV transition energies and dipole oscillator strengths using the excited-state coupled-cluster methods, including EOMCCSD (equation-of-motion coupled-cluster method with singles and doubles) and CR-EOMCCSD(T) (the completely renormalized EOMCC approach with singles, doubles, and non-iterative triples). For dipole-allowed transition energies, there is a very good agreement between experiment and theory. In particular, the CR-EOMCCSD(T) approach explains the blue shift in the electronic spectrum due to the formation of the non-chelated species after the UV irradiation of the chelated form of acetylacetone. Both experiment and CR-EOMCCSD(T) theory identify two among the seven non-chelated forms to be characterized by red-shifted UV transitions relative to the remaining five non-chelated isomers.

Incoherent light-induced self-organization of molecules.

Although coherent light is usually required for the self-organization of regular spatial patterns from optical beams, we show that peculiar light-matter interaction can break this evidence. In the traditional method of recording laser-induced periodic surface structures, a light intensity distribution is produced at the surface of a polymer film by an interference between two coherent optical beams. We report on the self-organization followed by propagation of a surface relief pattern. It is induced in a polymer film by using a low-power and small-size coherent beam assisted by a high-power and large-size incoherent and unpolarized beam. We demonstrate that we can obtain large size and well-organized patterns starting from a dissipative interaction. Our experiments open new directions to improving optical processing systems.

Multistate polarization addressing using a single beam in an azo polymer film.

Peculiar light-matter interactions can break the rule that a single beam polarization can address only two states in an optical memory device. Multistate storage of a single beam polarization is achieved using self-induced surface diffraction gratings in a photoactive polymer material. The grating orientation follows the incident light beam's polarization direction. The permanent self-induced surface relief grating can be read out in real time using the same laser beam.

[The new cemetery in Katyn: a permanent monument to the murder of Polish officers, including pharmacists. The authors' own report]. / Powstajaca nekropolia w Katyniu - trwalym pomnikiem mordu na oficerach polskich, takze farmaceutach. Relacja wlasna autorów.

Polish army officers were called up in 1939, due to German aggression against Poland. Those who were in eastern Poland which had been occupied but the Soviet Union since September 17th 1939, were captured by the Red Army and committed to the NKVD. They were imprisoned in several camps and murdered (nearly 25.000 persons) in April and May 1940. The prisoners from the camp in Kozelsk (over 4.400 persons) were shot in Katyn forest near Smolensk. The authors went there on April 19, 2000 and were attracted by the commemorative plaques to over 60 murdered pharmacists.

Resolving power of the human visual system to monochromatic stimuli.

The resolving power in monocular, foveal vision was found to depend on the size of a white light source made of two white rectangles separated by vertical black bar. The question arises whether the wavelength of light influences this dependence. An experiment was done on three subjects using six monochromatic lights the range 450-625 nm, and white light for control measurements. The diagram of the dependence of the minimal angle of resolution on the source size takes the shape of a biphasic curve, i.e. decreasing and constant function. The wavelength was found to have no impact on the curve shape or values. The data points obtained for white light coincide with those for monochromatic lights. The results confirm a thesis that all three colour mechanisms in the human visual system are stimulated and are active in spatial summation processes, but to a degree conditioned by a spectral sensitivity of the particular colour apparatus. It was confirmed that all colour mechanisms have potentially the same acuity but the axial chromatic aberration causes observed reduction of acuity.

Fulminant hepatic failure.

Fulminant hepatic failure is a complex clinical syndrome that has a diverse etiology, an unpredictable course, and a high mortality rate. The acutely ill patient admitted to the ICU with this condition often presents a challenge to the intensive care staff because of the life-threatening, multi-system complications. This article presents a review of the etiology, complications, and management of fulminant hepatic failure.

[The effect of new quaternary ammonium compounds on bacteria and fungi. 5: Synthesis of 3-methyl-n-alkylthiomethylpyridinium-, 1-methyl-3-n-alkylthiomethylimidazolium- and 1-ethyl-3-n-alkylthioimidazolinium chloride]. / Wirkung neuer quartärer Ammoniumverbindungen auf Bakterien und Pilze. Teil 5: Synthese von 3-Methyl-n-alkylthiomethylpyridinium-, 1-Methyl-3-n-alkylthiomethylimidazolinium- und 1-Ethyl-3-n-alkylthiomethylimidazoliniumchloride.

Synthesis of some chlorides indicated in headline and their antibacterial properties was described. Synthesis of quaternary pyridine and imidazoline chlorides was performed by reaction of chloromethyl-n-alkylthioether with 3-methylpyridine or 1-methyl- and 1-ethylimidazole. Antibacterial properties of obtained compounds was tested on 13 strains of bacteria and fungi. Chlorides with dodecyl radical indicated the best antibacterial activity.